SHUTTLE ENCOUNTERS MORE TECHNICAL PROBLEMS IN ORBIT

An orbiting laboratory that NASA hopes will one day help develop "Dick Tracyish" devices overheated like an old car on Tuesday.

So the space agency had to shut it down to let it cool.

NASA managers said they would give the lab another try today. They plan to turn the $25 million disc-shaped satellite back on until it gets too hot and has to be cooled off again.

Thats would give the lab an extra day to grow its ultra-pure semiconductors for faster and smaller communications devices.

The crew of the space shuttle Endeavour will delay their recapture of the lab until Thursday, costing some work on lower-priority experiments, NASA managers said. Endeavour has experienced more than a dozen technical problems since last Thursday's launch.

"We've had more than our share of the little hitches, but the good news is they haven't stopped us from getting done what needs to be done," shuttle Cmdr. David Walker said.

The lab, centerpiece of Endeavour's flight, was supposed to show off NASA's new attitude of "faster, better, cheaper."Lab managers took more risks and built fewer back-ups, but spent less money designing the satellite, NASA program manager Raymond Gavert said in July.

But designers may have miscalculated the heat generated by the lab's power supply, said project director Alex Ignatiev of the University of Houston. Temperatures reached about 158 degrees F., about nine degrees hotter than some of the computer controls could handle.

The miscalculation may be the result of NASA's attempt to fix problems that cropped up last year, when the lab - called the wake shield facility - was first flown, Ignatiev said.

In February 1994, the wake shield never got off the shuttle's robot arm because of control problems. So NASA added a battery and other devices that greatly increased the amount of power the lab produces, Ignatiev said.

Ken Kihlstrom, a professor of physics at Westmont College in California, called that an example of "the law of unintended consequences: You fix one thing and create unanticipated problems."

"Any time you're doing high technology, there are so many things that have to go right," Kihlstrom said.